In a compressed air supply system for a commercial vehicle, some components are specified to be maintenance-free for the lifetime of the vehicle, while other components have to be serviced at regular intervals that may be measured in time or in mileage. Those specifications are usually only valid for a certain range of usage scenarios. Usually, large safety margins are built into the specifications, so that a departure from the envisaged usage scenarios is unlikely to cause a premature breakdown of the component.
Due to the large safety margins, components are serviced more often than is really necessary. Their service life is not used up efficiently. On the other hand, reducing the safety margins will entail the danger that a component will fail prematurely during particularly heavy use. In this case, the vehicle will not be able to limp home, as many of its vital systems require compressed air to run.
The document KR 10 128 36 44 B1 discloses a method to predict wear of a ship engine by monitoring bearing abrasion. In components for compressed air systems, such a direct observation of wear during normal operation is usually not possible.
The document JP 2005 171 940 A discloses an engine maintenance time prediction device that weights time intervals with the average engine load during those time intervals. Since the wear of compressed air system components usually depends on several variables, such a weighting will not be accurate enough to reliably predict when components are due for maintenance.